One of the enemy sprites I did for Kaiju Big Battel: Fighto Fantasy. I was brought in relatively late in the game's development to do enemy sprites for the last few areas. The Cube Bot is a killer robot bearing the likeness archvillain himself, Dr. Cube. Well, just his head, but I guess that's enough.

The engine the game was done in has SNES-style constraints: it has a 256 color palette which backgrounds can make full use of, but sprites can only use 16 of those 256 colors at a time. It was a challenging set of constraints, and really made me appreciate the effort that had to go into pixel art back then to make it shine in spite of the limitations.

You can find the game here: https://store.steampowered.com/app/611710/Kaiju_Big_Battel_Fighto_Fantasy/